Light projector



A ril 8 1924. 1,489,646

. R. H. NEIL LIGHT PROJECTOR Filed Nov. 25 1922 INVENTOR 11 RUSSELL Jl. JY7A ATTORNEY lel rays of light with no diffusion 1f the Patented Apr. 8, 1924.

PATENT oer-ma.

aus'sntr. H. NEIL, or BERKELEY, cnmrcann.

near raomoron Apptleation and mum; at, 1922. Serial No 603,188.

To all whomit may concern:

Be it known that I, R 'ssELnH. NEIL, a

citizen of the United' States, residing at,

Berkeley, in the county. of Alameda and State of California, have invented certain new and useful Improvements in Light Pro-- jectors, of which the following is a specification.

My inventionis an improved light pro jector.

A parabolic reflector will transmit paralsource is a point of light at its focus. The

average light a. proximates the point source by placing the ight bulb at the focus of the parabaloid, but it is far from accurate because of the size of the incandescent filament.

' the point source in a parabolic reflector in The object of my invention is to produce a point of light from alight bulb b means of a roperly curved reflecting sur e which wi l focus the rays at a point and reflecting parallel rays.

In th' drawing in which my invention is illustrated I have shown the preferred form;

but it may be embodied in other forms, and in the specification and appended claims I wish to cover it in whatever form it may be embodied. Referring to the drawing i Figure 1 is a transverse, sectional view of m%reflector.

igure 2 is a transverse sectional view of a modified form of my invention.-

Figure 3 is a front view of my invention. 'Figure 4 is an enlarged front view of the light screen. 7

Referring more particularly t9 the drawing, the numeral 1 indicates a housing in which my reflector 2 is positioned. The light 3 is positioned within and'entirely enclosed by two ellipsoidal casings 4 and 5, the light being on the common focus of the two casings. The other focus of the casing 4 is at 6 which is on the, periphe of the casing 5. The other focus of the casm '5 is at 7 on the periphery of the casing. 4. penings 8 and 9 are formed in the-casings 4 and 5 respectively around the foci 7 and 6 respectively.

These openings allow the focused rays of, the casings 4 and 5 to pass outwardly, to be In actualpractice I have found that the 'proper curvature for-the casings 4 and 5 are ellipsoids of one-third eccentricity; that is, the distance between the foci equals onethird the major axis. To throw light on the road in front of the automobile, an opening 12 is5 provided in the front wall of the casm n the modified form of my invention shown in Figure 2, the light 15 is placed at one of the foci 16 of an ellipsoidal casing 17, the other focus of said casing being immediately adjacent the focus 16. A half parabolic reflector 18 is placed in the casing 1 in sucha position that its focus is at 16 and consequent-l will reflect the light in parallel rays with little diffusion. The light which is not reflected by the reflector 18 is thrown on the road immediately in front of the car. This is desirable for an automobile headlight where it is necessary to see objects at either side of the road.

Due to imperfections in the forming. of the reflecting casings and in the size .of the incandescent wire, it is not possible to get all of the rays to pass through the foci of said casings To obviate this difficulty, I insert a screen 20 in the openings 8 and 9 to diffuse all of the rays except those passing through the hole 21. Thus an almost perfect point of light is obtained. The glass around the hole 21 is either ground or sanded.

Having described my invention, I claim:

1. A light projector comprising a. light, a

project the light from said foci.

2. A li ht pro ectorcomprising a light, a pair of casings surrounding said li ht, said casings having apertures formed t erein, a

light screen positioned in said apertures, each casing having its focus in the aperture of the other casing, and reflectors adapted to project the light from said foci.

In testimony whereof I aflix my signature.

- RUSSELL H. NEIL. 

